Power-driven mechanism for operating type bars and other instrumentalities of typewriters or like machines



Oct. 30, 1951 H. J. HART POWER-DRIVEN MECHANISM FOR OPERATING TYPE BARS AND OT INSTRUMENTALITIES OF TYPEWRITERS OR LIKE MACHINES Filed July 1, 1949 INVENTOR Oct. 30, 1951 J, H 2,573,197

POWER-DRIVEN MECHANISM FOR OPERATING TYPE BARS AND OTHER INSTRUMENTALITIES OF TYPEWRITERS OR LIKE MACHINES Filed July 1; 1949' 3 Sheets-Sheet 2 Fig.5,

lNVENTOR Hen/7y J/{arZ Oct. 30, 1951 H. J. HART 2,573,197

POWER-DRIVEN MECHANISM FOR OPERATING TYPE BARS AND OTHER INSTRUMENTALITIES OF TYPEWRITERS OR LIKE MACHINES Filed July 1, 1949 5 Sheets-Sheet 3 6. Fg. Z I 52 55 i 51 54 56, 7 \\g\ Fig.8. 75

a. I INVENTOR Z4,

ATTO Patented Oct. 30, 1951 POWER-DRIVEN MECHANISM FOR OPERAT- ING TYPE BARS AND OTHERINSTRUMEN- TALI'TIES V MACHINES F TYPEWRITERS on LIKE Henry J. Hart, West Hartford, Conn.,assignor to Royal Typewriter Company, Inc., New York, N. Y., acorporation of New York Application July 1, 1949, Serial No. 102,634

' 10 Claims. (01. 197-17.)v

- This invention relates to power driven mechanism for operating type bars and other instrumentalities of typewriter or like machines.

- In one of its aspects the invention relates more particularly to an improved mechanism for transmitting drive from a constant speed motor to a continuously'driven rotary driving member embodying'a novel and efiective devices for varying the rotative speed of the driver -so as to'vary the operating efiort'delivered to the type bars or other instrument'alities.

One object of the invention is to provide mechanism for varying the Speed of a driver of the kind referred to above, including a V-type groove pulley having sections divided from each other medially and being relatively shiftable or displaceable axially so as to vary the width of I the pulley groove and hence the effective diameter at which a cooperating belt engages the pulley.

In another of its aspects the invention relates more particularly to improvements in power generating or transmitting mechanism of the kind disclosed in the copending application of William H. Kupper, Serial No. 6,066, filed February 3, 1948, now Patent No. 2,567,945, dated September 18, 1951. The mechanism disclosed'in the copending application includes a driving member in the form of a continuously rotating snatch r011 adapt-ed to transmit drive to a typewriter instru mentality through a toothed driven element adapted to be moved, under key control, into a snatch roll tooth interspace. Improvements similar to those disclosed in the present application as being embodied in type bar operating mechanism are disclosed and claimed generally in the copending application of Henry J. Hart, Serial No. 98,738, filed June 13, 1949, now Patent No. 2,563,722, dated August 7, 1951, in which the improvements also are claimed as being embodied in escapement operating mechanism.

Another object of the present invention is to provide a new and improved arrangement for varying or adjusting the amount of driving effort imposed upon or transmitted to a typing member by a continuously rotating toothed snatch roll.

Another object of the invention is to provide adjusting or drive-efiort-varying means of the kind referred to,.by which the adjustment is effected by variably limiting the extent to which a toothed driven element is moved into a tooth interspace on a rotating snatch roll.

Another object of the invention is to provide a belt and pulley drive mechanism for a poweroperated typewriter or like machine including a novel and improved belt tensioning device.

Other objects of the invention will become apparent from a reading of the following description of a preferred embodiment of the invention, the appended claims, and the accom panying drawings in which: a

Figure 1 is'a view, partly in elevation and, partly in vertical section, fore-and-aft of a type-'- writer embodying the invention, showing only some of the conventional or standard typewriter" parts in order to=illustrate the application of mechanism embodying the invention to atype;

writercon'structiony Figure 2 is a detail perspective view of a pulley" section and associated'parts shown in separated" relation;

Figure 3 is a fragmentary vertical sectional view on the line 3-3 of Figure 1, drawn-on an;

enlarged scale;

-Figure 91 is'a fragmentary view showing parts in section on the line 44 of Figure 3 andfsh'owg-Q ing a portion of an associated typewriter ;frame or mask side wall; 1

1 Figure 5 is a developed-view of an adjusting knob, showing an associated part of a frame wall;

in horizontal section;

Figure 6 is a vertical section takenend-to-end of the machine on the irregular line 5-4; of Figure 1;

Figure? is a detail perspective view of a por tion of a preferred form of'fiexiblebelt;

Figure 8 is a horizontal sectional 'view on -the line*88 of Figure 1, showing anidler pulley:

belt tensioning device; and

Figure 9 is a fragmentary for-and-aft a tional View 'a ype bar'operating mechani m some parts being shown in elevation. l

The invention may be embodied in typewriters or like machines of various kinds. For the -purposes of illustration, the invention is shown asbeing embodiedin an oiiice type typewriter having, except for the power mechanism to be described, many features in common with th'e well invention may be coordinated with other of a typewriter construction.

The known construction illustrated includes'a main frame A onwhic'h a carriage B equipped} with a platen C is mounted for letter spacing and return movements by means of atop-rail l='se cured to the carriage, and rolling upon balls-2,

which inturn are adapted to roll o'n'a frame mounted' 'bottom rail" or track3. i

OFFICE The carriage may be driven toward the left, that is, in the letter-spacing direction, by any suitable mechanism, for example, by a spring barrel and draw band of known or suitable construction (not shown), under the control of suitable esca'pement mechanism operated, for example, a disclosed in the aforementioned copending application of Henry J. Hart, Serial No. 98,738, filed June 13, 1949.

Returning of the carriagetoward the right may be eifected by power controlled from the typewriter keyboard, for exampleyby mechanism" of the kind disclosed in the copending application of Henr J. Hart, Serial No. 21,476, filedAprillB, 1948, now Patent No. 2,567,937, dated September 18, 1951.

The machine is provided withv the usual .complement of type bars, one of which is shown at 4 in Figures 1 and 9 as being pivoted at 5 on a support or segment 6 equipped with a type bar abutment or banking ring 1. Normally the type bar. 4 is in the position shown in Figure l with the type head resting upon a cushion 8. The invention will be described in connection with the operation of type bars or other typing members, :1

but it will be understood that features of the invention may be utilized in the operation of other typewriter or like machine instrumentalities.

Power for operating hte type bars or other instrumentalities is supplied by an electric motor D, and is transmitted through a mechanism train or connections generally designated E to an actuating mechanism generally designated F. The

mechanism F is generally similar to mechanism described and claimed in copending application Serial No. 98,738 referred to above, and is similar to but embodies improvements in mechanism disclosed in the aforementioned copending application of William H. Kupper, Serial No. 6,066, filed February 3, 1948. It includes a continuously operating driving element and controllable driving connections, which normally are inoperative or ineffective, but which ma be conditioned by theoperator to eflect operative driving connection between the continuously moving driving member and the train of connections E. The driver is constituted by a continuously rotating element, more particularly a toothed snatch roll or bar 9, which may be of known form, and which is adapted to be driven in the direction of the arrow a in Figures 1 and 9 by the electric motor D.

The mechanism for transmitting drive from the driver 9 to each of the type bars 4 includes an actuator II] which extends fore-and-aft of the typewriter and above the member 9. The actuator I is pivoted as at H to a lever l2 at a point off-set relatively to the pivotal mounting I3 of the lever on a fixed frame cross bar 14. The actuator has a forwardly extending part l5 projecting under an abutment or guide plate [6 mounted by screws I! on the frame A to extend parallel to the snatch roll 9; A spring [8, interposed between the front end of the actuator l0 and the frame A at a point not shown, yieldably urges the actuator to rock clockwise, and thus normally maintains the actuator in the position shown in Figures 1 and 9 with its front end part I5v bearing against the abutment or guide plate l6.- Another abutment I9 is disposed below the abutment IS.

A link 20, pivotally connected to the lever I2 and the heel of the type-bar 4 at 2| and 22- respectively, causes the type bar to be driven clockber.

- 3 member 9includes an-interponent pawl 23, pivoted as at 24 on the actuator. A spring 25, an-

- chored to the actuator l0 and connected to the pawl 23, biases or urges the latter to rock clockwise so as to. move. its nose 23 into engagement with-the-snatch roll 9.

Normally, the pawl is maintained out of'engagement with the snatch roll by the restraining action of a control ele- 'ment or trigger 26 which is pivoted as at 21 on theiactuator III. In the normal position of the trigger, its rear end 28 engages a holding surface 29 on the pawl so as to prevent the spring from rocking the pawl element 23 into transient drive-transmitting engagement or connection with the drivin member 9. The pawl 23 is formed with an inclined resetter cam face 30 which is located just below the holding'surface 29, and which is acted upon by the trigger for rocking the pawl counterclockwise, and thus resetting it in normal, inoperativeposition.

Operator controlled means including a manually operable key 3| pivoted at 32 on the frame A is provided for bringing about operative driving connection between the driver 9 and the actuator ill. The key 31 has an upward projection 33 disposed behind anarm 34 of an operating lever 35, pivoted as at 33 on a frame-mounted cross bar 37. The lever 35 has another arm 38 on which a limber dog or flipper 39 is pivoted at 49. A spring M urges the limber dog 39 to rock clockwise to yieldingably retain it in its normal position of rest against. a limit stop 42. The dog 39 can swing counterclockwise from, the position shown in Figures 1 and 9, but cannot move clockwise from this position. A returning spring 43, interposed between the key 3! and a short arm 44 on the lever 35, yieldably holds the lever 35 and the key 3! in their normal positions. In the normal positions of the parts, the lower end of the limber dog 39 overlies a contact car 44 on the actuator l0.

In operation, when the key 3| is depressed,

; ger .26 into engagement with the abutment I9.

This causes the trigger to be rocked clockwise about its pivotZT, so as to release the pawl 23, which is then moved by the spring 25 into engagement with the snatchv roll 9. The snatch roll then drives the pawl 23 and actuator I0 as a unit so as to rock the lever l2 and operate the link 28 and-type bar 4. When the pawl 23 is cast off from engagement with the snatch roll 9, the spring [8 lifts the actuator It] to bring the trigger 23 into engagement with the upper, trigger-resetting abutment I6. This causes the trigger 26 to'be rocked counterclockwise, so as to move its end 28 against the resetting cam face 39 of the pawl 23, thereby restoring the latter to its inactive position. The parts ofthe mechanism F will then be returned to their normal positions by a spring (not shown) but which may be interposedbetween a part at the rear of the frame A and a link 45 connected to the lever I2.

Means are provided fol-adjusting or varying the amount of driving impulse delivered: to the individual pawl 23 by the snatch rolll9. In accordance with the invention, the individual variation or adjustment is effected by variably limits ing the extent to which the actuator pawl nose 23 enters a tooth interspace on the snatchroll 9 under the urge of the springi25 when the re"- straint of the trigger 26 on the pawl ,23 is discontinued. In theform shown, the actuatorrlll is provided with a downwardly extendingstop element or finger 46 which vis disposed in? front of and normally out of contact with a down-; wardly extending stop part, heel, or fingers/41 on the pawl 23. When the pawl.23 rocked clockwise by thespring 25 so as to move the pawl nose 23, into a snatch roll tooth interspace, the .pawl stop 41 moves toward the actuator stop 46, which may be so positioned as to be engaged by the stop 41 to arrest rocking of the pawl 23 before the toothi23 moves to. the root of theisnatch roll tooth interspace. By variably positioning one of the. stops 46,41, e. g., by bending-the stop, 46 towards or awayofrom the stop 41, the extent towhich the pawltooth 23 enters the tooth in-. terspace can be varied. Consequently, the :angle through which the snatch roll rotates whilein contact with the pawl, which determines the amount of driving of the pawl Y23 and the actuator In by the snatch roll 9, can be varied. Any suitable means or construction may be provided for'adjusting one of the stops 46, relatively to the other. In the preferred construction the stop 46 is formed integrally with the actuaton l6 so as to be bendable toward or awayfrom the The resultant driving of the pawl 23 and actuator It] by the snatch roll 9 accordingly will be of relatively short duration. On the other hand, if the actuator finger 46 is bent to the position shown in dotted lines at 46 in Figure 9, the pawl tooth Z9 will be permitted to make a relatively deep entrance into a tooth interspace, and the driving of the pawl and actuator accordingly will be relatively greater. 4

In typewriters or like machines in which all or some of the instrumentalities to be operated, e. g., escapement mechanism, carriage return mechanism, tabulating mechanism, as well as typing mechanism, are operated by power, it is desirable to provide means for varying collectively the driving impulse transmitted to the several actuator pawls correspondingto the pawl 23 and associated with the other type barsand mechanisms referred to. In accordance-with a further feature of the invention, new and improved mechanism is provided for varying the rotative speed of the snatch roll- 9 so fl'as consequently to vary the intensity of the impulses transmitted to the actuator pawls. The electric motor D preferably is of a kind to operate at a substantially constant speed, and the variation of the snatch roll speed is accomplished by means of variable ratio drive mechanism embodied in the transmission train E interposed between the constant speed motor -D and the actuating mechanism F.

As shown in Figure 6, the motor D is mounted on the frame base by means including'a bracket 48 through which the motor shaft 49 extends,- Secured to the shaft 49 is a small pulley-50 which drives a belt 5| trained around a larger pulley- 52 the hub 53 of which is fitted with abearing liner or bushing 54 journaled on a stub axle 55 secured to a standard 56. The standard 56 may be formed with an oil passage 51. i v

The portion of the pulley hub 53 extending to the rightlof the pulley 52 is formed as another; small pulley 58 which is engaged by a belt 5.9. trained around a larger pulley 60 keyed .to a. shaft 6|. The shaft 6| is rotatably mounted by a.bearing 62 carried by the standard 56, and a'bearing 63 on another standard part 64.. The bearings 62 and 63 may be lubricated through oil passages 65. The standards 56 and-64. may be formed in one piece, secured to the. frame base by screws 66. l a; .Secured to the outeror right-hand end ofthe shaft 6| by means of a set screw 66 is a V-type groove pulley 61 which is driven at a substantially constant speed by the motor D through the. pulleys 50, 52, 58 and 69, the belts 5| and 59, and the shaft 6|. An antiiriction thrust bearing 6|! is interposed between the pulley 61 and the standard 64. A V.-type belt 68 is trained around the constant speed pulley 61 and another V. type groove pulley generally designated 69 connected to the snatch roll 9. .The belt 68. is maintained under substantially constant. tensionnby, a'belt tightener or vtensioner generally designated 76, and illustratedin Figures .1 and 8, .Thebeltten-r sioner comprises a rock frame]! pivoted asat 12 on a frame-mounted bracket 13, an idlerrpula ley "journaled .at 15 at. the rear endlof the. frame H, and another idler pulley 16 journaled at 11 on the rock frame H in front of therock frame pivot .7 2. The idler pulley M is positioned above and the idler pulley 16 is positioned below the upper stretch of the belt 68. A spring 1.8- interposed between V. the front end. of the rock frame H- and a fixed part 18 on the machine frame urges the rock frame in a clockwise direciton as'viewed in Figure 1, causing the pulley 14: to press downwardly and the pulley 16 to press upwardly against the upper stretch .of the belt68, thereby maintaining the belt under sub-,, stantially constant tension so that it will be driven by the pulley 61 at a substantially constant speed. a a I 1 Variation of the snatch roll speed iseffected by varying the speed of the pulley 69 and, in accordance with the invention, the pulley speed is varied by adjusting the width of the V groove in the pulley 69 so as to vary the effective diameter at which the belt 68 engages the pulley 169. To this end the pulley 69 is constructed "and coordinated with the snatch roll 9 itself and with adjusting mechanism to be described, in a novel manner enablingthe adjustments tobemade effectively, The adjusting mechanism is so interrelated with thepulley 69, the snatch roll and other parts of the power mechanism as to require no substantial additional space and so as to enable adjustments to be made from the outside of the typewriter frame when the snatch roll is running, if so desired, As shown in Figure 3, the snatch r0119 is provided with journal portions or pins 19 and 86. secured respectively in bores BI and 82 formed in'the ends of the snatch roll. The pinextends through the hub 83 'of one section 84 of the pulley 69, and is free to slide or shift relatively axially with respect to the pulley section- 84, The hub '83 is journaled in a bearing liner Bicarriedby a cap 86 mounted in afixed frame 75 wall 81. The bearing85 is formed with a flange 7 or 'rim 88 which abuts against a mating shoulder inthe cap 85 to hold the'bearing against move ment toward the right, as viewed in Figure 3. Fitted to the hub 83 after assembly of the parts is a flange or rim 89 which abuts the left-hand end of the bearing liner 85.

Thepulley 89 includes another section 90 separated from the section 84 on armedian plane and formed with a hub 9| which is fitted on a reduced part of the right-hand end of the snatch roll journal portion 80 as shown inIFigu'res 2 and 3. The pulley section hub 9| is heldtightly against a. shoulder 92 on the journal portion 80 bymeans of a connecting plate 93, which fits on a fiatpartof the journal portion 80, and a securing screw 94. The comiecting plate 98 is formed with a slot95 which receives for sliding movement a .pin 98 anchored as at 91 to the pulley section 84, the pin passing freely through a hole 98. in the pulley section 90. Thus the pulley sections 84 and 90 are relatively displaceable axially with respect to each other, but are constrained to rotate together by the connection provided by the pin 96. The pulley section .90 is fixed to the snatch roll 9 through the journal portion 80 of the snatch roll so as to rotate and also to shift axially with the snatch roll.

The journal portion 19 at the left end of th snatch roll 9 extends through a bearing 99 supported by .a cap I mounted on another fixed frame wall 81 and having a sleeve IOI extending to the left of the associated wall 81'. The journal portion I9 is free to rotate in and shift axially with respect .to the bearing 99, and the outer end of the journal portion abuts an anti-. friction ball I02 received in a socket or seat I03 formed. in the adjacent end of an adjusting screw I04 having threaded engagement with internal threads I05 formed in the cap sleeve IOI. A spring I06, interposed between the left-hand end of the hub 83 of the pulley section 84 and the root of a counterbore I01 formed in the right end of the snatch roll 9, constantly urges the snatch roll 9 toward the left so that the journal portion I9 presses against and is backed up by the antifriction ball I02.

The adjusting screw I04 is rotatable in the sleeve IOI to convert its rotation to linear motion so as to shift the snatch roll 9 towardthe right against the urge of the spring I08, thereby also shifting the pulley section 90 of the adjustable pulley 69 axially away from the companion pulley section 84 so as to decrease the effective diameter at which the pulley 69 is engaged by the V belt 68. Conversely, when the screw device I04 is backed off so as to retract the antifriction ball I02 the spring I08 acts in a follow-up manner so as to shift the snatch roll 9 toward the left and bring the pulley section 90 closer to the companion pulley section 84, thereby increasing the effective diameter at which the belt 08 engages the pulley 69.

The rotation of the screw I04 is facilitated by the provision of a knurled adjusting knob device I08 having a hub I09 fitted on a shank N0 of the screw I04, and secured to the shank by a set screw III. The knob I08 is indexed or provided with scale markings -II2 which can be read in connection with a pointer I I3 which conveniently may be bent or pressed outwardly from' the adjacent frame mask or cover portion I14. In order to limit the rotation of the knob I08 in a direction causing the screw I04 to move to the left, the frame mask portion H4 is formed with astop projection I whichis positioned to be engaged :by the set screw 'I'II when the latter has been moved to the left coincidental to leftward movement of the screw I04 to a predetermined limit position. Movement of the screw I04 in the opposite direction is limited by engagement of the right-hand end IIS of the knob hub I09 with the left-hand end II! of the sleeve IOI. Figure 3 shows the'parts in full lines in intermediate positions of adjustment wherein the snatch roll 9 is so positioned that it may be moved either toward the right to occupy the position indicated in dotted lines, or toward the left.

If it is desired to make no carbon copies or only a minimum number of carbon copies when typing,.the knob I08 is turned so as to bring the index 0 (zero) opposite the pointer H3, thus moving the ball I02 to the left until rotation of the knob is arrested by engagement Of the set screw III with the stop projection H5. Movement of the ball I02 to the left will enable the spring I06 to move the snatch roll, the journal portion 80, and the pulley section to the left so as to reduce the width of the V groove in the pulley 89 and-increase the effective diameter at which the belt .68 engages the pulley. Inasmuch as the belt 88 is driven at a constant speed as explained previously, the increasing ofvthe effective diameter of the pulley 89 effects a transmission ratio change, reducing the rotative speed of the snatch roll 9. When the snatch roll is rotating at'a relatively low speed, the impulse delivered to the pawl 23 and the associated parts is; relatively small so that the type bar 4 is driven to printing position at such speed as to produce a relatively light typing impact. If it should be desired to make a large number of carbon copies, say twenty, the knob I08 is turned in the 'opposite direction until the number 20 on the knob registers with the pointer II3. This will move the ball I02 toward the right so as to push the snatch roll and connected parts toward the right against the urge of the yielding spring I00. The parts thus moved toward the right include the pulley section 90, which is relatively separated from its companion section 84, thus increasing the width of the pulley groove and reducing the effective diameter at which the belt 88 engages the pulley 69. In this way a driving ratio change is effected, causing the snatch roll 9 to be driven at an increased speed so as to deliver increased impulses to the pawl 23 and operate the type bar 4 with greater force and more impact upon the work sheets. It is apparent that varying intermediate degrees of type bar impact may be obtained by setting the knob I 08 so that thepointer II3 registers with appropriately selected scale indicia between 0 and 20 on the knob.

Figure 6 shows parts of a power driven carriage returning mechanism which is not claimed in the present application but which is closely associated with the power transmitting mechanism E and which therefore may be described briefly. Secured to the bracket 56 by screws H8 is an arbor II9 formed with a sleeve part I20 concentric with the shaft 0|. The sleeve part I20 mounts a bearing bushing I2I on which is journaled a hub I22 of a winding drum I23 formed with a groove I24 which receives a draw band I25. The band I25 may be connected to the carriage B, for example as shown in copending application Serial No. 21,476 previously referred to. Secured to the shaft 6| by threads I26 is a'clutch ring carrier disk I2! surroundedby a flange I28 on the drum I23. A split clutch ring I29 is connected to the disk I2'I at a point not shown, so as to have substantially semicircular or arcuate portions disposed within, but normally out of engagement with, the drum flange I28. The ring portions may be expanded to engage the flange I28 by moving a cone I30 axially to the left on the shaft GI so as to spread clutch-engaging fingers I3I which operate through connections, not shown, to expand the ring I29. The cone I30 may be moved to the left through the medium of a fork I32 operatively connected to a collar I33 on the shaft BI and being shiftable toward the left to press against an antifriction ball bearing assembly I34 which, in turn, presses against the cone I30. Key-controlled actuating mechanism of the general character disclosed in copending application 21,476 may be interposed between the fork I32 and the actuator and pawl mechanism shown in Figure 9 of the present application.

The mechanism disclosed embodies the invention in a preferred formLbut it is intended that the disclosure be illustrative rather than definitive, the invention being defined in the claims.

I claim:

1. In a power operating mechanism for a typewriter or like machine, a rotatable toothed snatch roll; a typing member to be operated by said snatch roll; means for transmitting drive from said snatch roll to said typing member including an interponent having a contact part normally disengaged from said snatch roll but being engageable therewith by entrance into a tooth interspace thereof; operator controlled means for effecting such engagement of said interponent part with said snatch roll; an adjustable stop separate from said operator controlled means and said Snatch roll; and another part on said interponent engageable with said stop for variably limiting the extent of entrance of said interponent contact part into a snatch roll tooth interspace, adjustment of said stop thereby variably determining the extent of driving of said interponent and said typing member by said snatch roll.

2. In a power operating mechanism for a typewriter or like machine, a rotatable toothed snatch roll; a typing member to be operated by said snatch roll; an actuator connected to said typing member and being normally disconnected from said snatch roll; a spring urged interponent movably mounted on said actuator and having a contact part normally disengaged from said snatch roll but being engageable therewith under spring urge by entrance into a tooth interspace thereof; operator controlled means-"normally restraining said interponent from engagement with said snatch roll but being operable for discontinuing its. restraint to enable the spring urge to effect engagement of said interponent contact part with said snatch roll ;-an adjustable stop on said actuator; and another part on said interponent engageable with said stop for variably limiting spring-urgd movement of said interponent re1atively to said actuator, adjustment of said stop variably determining the extent to which said interponent contact part can be moved by spring urge into a snatch roll tooth interspace, and consequently variably determining the extent of driving of said interponent, said actuator, and said typing member by said snatch roll.

3. In a power operating mechanism for a typewriter or like machine, a rotatable toothed snatch roll; a typing member to be operated by said snatch r011; an actuator connected to said typin drivingly connecting said motor to said pulley. i

member and being normally disconnected from said snatch roll; a spring urged interponent movably mounted on said actuator and having a con-'- tact part normally disengaged from said snatch roll but being engageable therewith under spring urge by entrance into a tooth interspace thereof; operator controlled means normally restraining said interponent from engagement with said snatch roll, but being operable for discontinuing its restraint to enable the spring urge to efiect engagement of said interponent contact part with said snatch roll; a first stop element on said actuator; and a second stop element on said interponent engageable with said first stop element for limiting spring-urged movement of said interponent relatively to said actuator and thus limiting the extent of entrance of said interponent contact part into a snatch roll tooth interspace and determining the extent'of driving of said interponent, said actuator, and said typing member by said snatch roll, one of said stop elements being bendable towards and away from the other of said stop elements for varying the limit of entrance of said interponent contact part into a snatch roll tooth interspace.

4. In a power operated typewriter or like machine, an instrumentality to be operated; a driving member; means .journalling said driving member for rotation; means operatively connected to said instrumentality and being transiently connectible to said driving member for transmitting drive therefrom to said instrumentality; a V type groove pulley journalled for ro-- tation at one endof and coaxially with said driving member and being drivingly connected thereto and divided medially of the groove to be constituted by two sections; means mounting one of said sections for axial displacement relative to the other of said sections for varying the width 7 of said groove; an adjusting device mounted at the other end of and coaxial with said driving member; means for transmitting motion from said adjusting device axially through said driving member to said one of said sections; a motor; and a belt drivingly connecting said motor to said pulley.

5. In a power operated typewriter or like machine, an instrumentality to be operated; a driving member; means journalling said driving member for rotation; means operatively connected to said instrumentality and being transiently connectible to said driving member forv transmitting drive therefrom to said instrumentality; a V type groove pulley journalled forrotation at one end of and coaxially with said driving member and'being drivingly connectedthereto and divided medially of the groove to be constituted by two sections; means mounting one of said sections for axial displacement relative to the other of said sections for varying the width of said groove; a rotatable adjusting device mounted at the other end of and coaxial with said driving member; means including a screw device for converting rotation of said adjusting device to linear motion and transmitting the linear motion through said driving member to said one of said sections; a motor; and a belt 6. In a power operated typewriter or like ma chine, an instrumentality to be operated; a driving member; means 'journalling said driving member for rotation; means operatively connected to said instrumentality and being transiently connectible to said driving member for transmitting drive therefrom to said instrumen- ,tality; av type groove pulley journalled for rotation at one end of and coaxially with said driving member and being drivingly connected ,thereto and divided medially of the groove to be constituted by two sections; means mounting one .of said sections for axial displacementrelative'to the other of said sections for varying th width of said groove; a spring urging said one of said sections axially in one'direction with respect to the other of said sections; a rotatable adjusting device mounted at the other end of and coaxial with said driving member; means including a screw device for converting rotation of saidadjusting device to linear motion and transmitting the linear motion through said driving member to said one of said sections for moving the latter axially in the opposite direction against the urge of said spring; a motor; and a belt drivingly conmeeting said motor to said pulley.

7. In a power operated typewriter or like machine, an instrumentality to be operated; a pair of axially aligned spaced bearings; a rotatable driving member having journal portions at its opposite ends mounted respectively in said bearings forboth rotation and axial shifting; a V type groove pulley mounted on'said member and comprising two mutually axially displaceable pulley sections, one of said sections being connected to said member for concurrent rotation-therewith and being constrained against axial movement relatively to said member, the other of said sec tions being shiftable axially relatively to said member; a spring urging said driving member and said one of said pulley sections axially toward one end of said member; a fixed internally threaded sleeve axially aligned with the bearing adjacent said end of said member; adjusting means including a screw having threaded engagement with said sleeve and being rotatable for pushing said member and said one of said sec tions axially against the urge of said spring for varying the width of the pulley groove; amotor; and a belt driven by said motor and engaging the walls of the pulley groove for driving said pulley and said driving member.

8. In a power operated typewriter or like machine, an instrumentality to be operated; a pair of axially aligned spaced bearings; a rotatable driving member having journal portions at its opposite ends mounted respectively in said bearings for both rotation and axial shifting; a V type groove pulley mounted on said member and comprising two mutually axially displaceable pulley sections, one of said sections being connected to said member for concurrent rotation therewith and being constrained against axial movement relatively to said member, the other of said sections being shiftable axially relatively to said member; a spring urging said driving member and said one of said pulley sections axially toward one end of saidmember; a fixed internally threaded sleeve axially aligned with the bearing adjacent said end of said member; adjusting means including a; screw having threaded engagement with saidsleeve and having a seat in its end adjacent said one end-of said member, and an anti-friction ball in saidseat engaging said one end of said member, rotation of said screw in one direction efiecting pushing of said ball, said driving member, and said one of said sections axially against. the, urge of; said spring for varying the width of the pulley groove; a motor; and a belt driven by said motor and engaging the walls of the pulley groove for driving said pulley and said driving member.

9. In a power operated typewriter or like machine, an instrumentality to be operated; a pair of axially aligned spaced bearings; a rotatable driving member having journal portions at its opposite ends mounted respectively in said bearings for both rotation and axial shifting; a V type groove pulley mounted on saidmember and comprising two mutually axially displaceable pulley sections, one of said sections being connected to said member for concurrent rotation therewith and being constrained against axial movement relatively to said member, the other of said sections being shiftable axially relatively to said member; a spring urging said driving member and said one of said pulley sections axially toward one end of said member; a fixed internally threaded sleeve axially aligned with the bearing adjacent said'end of said member; and adjusting means including a screw having threaded engagement with said sleeve and being rotatable for pushing said member and said one of said sections axially against the urge of said spring for varying the width of the pulley groove, an adjusting knob, a set screw for securing said knob to said adjusting screw, and a fixed stop engageable by said set screw for limitingrotation of said knob and said adjusting screw in one direction.

10. In a power operated typewriter or like machine, an instrumentality to be operated; a driving member; means journalling said driving member for rotation; means operatively connected to said instrumentality and being transiently connectible to said driving member for transmitting drive therefrom to said instrumentality; a V type groove pulley journalled for rotation at one end of and coaxially with said driving member and being drivingly connected thereto and divided medially of the groove to be constituted by two sections; means mounting one of said sections for axial displacement relative to the other of said sections for varying the width of said groove; a manually rotatable, scale marked adjusting device mounted at the other end of and coaxial with said driving member; means including a screw device for converting rotation of said adjusting device to linear motion and transmitting the linear motion through said driving member to said one of said sections; a motor; and a belt drivingly connecting said motor to said pulley.

=I-IENRY J. HART.

REFERENCES CITED The following references are of record in the file of this patent:

- UNITED STATES PATENTS Number Name Date 589,003 Luther Aug. 31, 1897 1,202,227 Sandifur Oct. 24, 1916 1,737,439 Stickney Nov. 26, 1929 1,984,410 I-Iart Dec. 18, 1934 2,170,212 Pfleger Aug. 22, 1939 2,278,739 Reeves -Apr. 7, 1942. 2,362,138 Kavle NOV. 7, 1944 

